August. The pale-yellow egg masses are arranged in a continuous linear series of tightly folded strings measuring 4 mm high and 50 mm long, and are deposited on clumps of algae or pebbles. Individual egg capsules, 0.15 mm in diameter, contain a zygote 0.09 mm in diameter and are suspended in a gelatinous matrix. Free swimming veligers hatched within 4 to 6 days following deposition. Foraging fish are the major predators of juvenile Cerithium caeruleum in the Sinai Red Sea. Taylor and Reid found the muricid, Muricodrupa funiculus, to be the major predator of adult populations in the Sudanese Red Sea. They observed that aggregative feeding by Muricodrupa on adults of C. caeruleum was common, with as many as five predators being involved. Adult prey were attacked through the aperture, while smaller individuals were usually drilled through the spire. Due to the thick outer lip and heavily armored shell, it is unlikely that adults can be eaten by most crabs. Ecology This species usually occurs in large populations on intertidal rocky shelfs with a thin covering of sediment and is frequently mentioned in ecological studies. It is common in the upper intertidal zone on beach stones and slabs in the Gulf of Aqaba. Ayal and Safriel found populations with densities as high as 300 per m2 along the Sinai coast, while Taylor and Reid recorded densities up to 54 per m2 near Port Sudan, Sudan. Chelazzi and Vannini documented its vertical zonation and algal associations on intertidal rocky platforms in southern Somalia. A comprehensive account of the ecology of C. caeruleum occurs in Ayal and Safriel, who studied cerithiid habitats in the Sinai peninsula, Red Sea. They recorded that C. caeruleum lived to the lee of wide platforms in solution basins and tidal pools on surfaces covered with sediment, and was very active during ebbs, but aggregated or burrowed during flows. Cerithium caeruleum occurs along a wide range of environmental gradients and occupies a wide vertical range. Geographic Distribution This species is confined to the continental margins of the western Indian Ocean where it is found as far south as Natal and Madagascar. It also occurs on Aldabra Atoll and in the Red Sea and Persian Gulf, extending eastward to the coasts of Pakistan and western India. Fun Facts about The Name This species, Cerithium caeruleum, is primarily referred to as Cerithium caeruleum Sowerby, 1855 in literature, but it also